Valve seat sealing structure

Abstract

The invention discloses a valve seat sealing structure with longer service life. The valve seat sealing structure comprises a valve seat ring, and a gate or a ball, wherein the valve seat ring is provided with a seal ring with a triangular section, and a guard ring made of a polytetrafluoroethylene or nylon material opposite to the surface of the gate or the ball; the compressive strength of the guard ring is higher than that of the seal ring; the guard ring is positioned on the inner side of the seal ring; and a contact surface between the guard ring and the gate or the ball is provided with a groove communicating the inside and outside of the guard ring and serving as a pressure balancing channel. A valve with the sealing structure has longer service life, and can rotate throughout the year more reliably; the operating torque of the valve is properly reduced, and the valve is convenient to open and close; and the valve can normally work under the condition that a transmission medium is dirty and disordered, the application range of the valve is widened, and the valve seat sealing structure is mainly used for flat gate valves or ball valves.

Description

technical field [0001] The invention relates to a flat gate valve or a ball valve, in particular to a valve seat of a flat gate valve or a ball valve. Background technique [0002] The main working principle of the slab gate valve is similar to that of the fixed ball valve. The seat ring of the valve seat is pushed by the fluid pressure and is tightly attached to the gate or the ball. The soft sealing material embedded in the seat ring groove on the seat ring will be in contact with the gate or The spheres touch to form a seal. [0003] Ordinary slab gate valves generally use an embedded method to fix the O-ring at the valve seat to form a seal. When the valve is sealed, the O-ring of the valve seat is deformed under the action of the fluid pressure, and it is tightly attached to the gate to form a sealing surface. However, the deformation of the valve seat is generally uncontrolled at this time, and the amount of deformation is mainly determined by the mechanical properti...

AI Technical Summary

Problems solved by technology

However, the deformation of the valve seat is generally uncontrolled at this time, and the amount of deformation is mainly determined by the mechanical properties of the material of the O-ring. From a microscopic point of view, after deformation, there is a shearing action between the O-ring and the notch of the seat ring groove. During the long-term use of the valve, the deformation of the O-ring will increase due to pressure changes, which will cause the O-ring to be worn by the notch of the seat ring and appear notches, which will eventually lead to the failure of the main seal of the valve.

[0004] In the same way, the O-ring of ordinary ball valves is also prone to shear and abnormal wear at the notch of the seat ring, which eventually leads to failure of the main seal of the valve.

[0005] In addition, when the fluid pressure is high, the deformation of the O-ring increases, the contact surface between the O-ring and the gate or the ball increases, and the operating torque of the valve increases, which is inconvenient for the valve to open and close.

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